1. Technical Field
The present invention relates to analog-digital conversion, and particularly to analog-to-digital conversion by which a conventional oversampled, fed back analog-to-digital conversion (e.g. a sigma-delta conversion) is improved.
2. Background Information
In conventional single-bit sigma-delta analog-to-digital converters (hereinafter also designated as single-bit sigma-delta converters), if there is too high a drive inside the analog-to-digital converter, impermissibly high signal levels occur, leading to overdrive of an amplifier used inside the analog-to-digital converter, so the input signal has to be restricted. The input signal is in this case typically restricted by −3 dBFS.
As a single-bit sigma-delta converter has as substantial advantages a linear single-bit digital-to-analog conversion and a surface area requirement which is small compared to other converters, if it is configured as a semi-conductor circuit, the disadvantageous restriction or attenuating of the input signal mentioned above is allowed for in current applications. A substantial disadvantage of this restriction is that a maximum permissible input signal must be below a possible value of a provided reference voltage for a required signal-to-noise ratio. An allowed noise power within a useful frequency band of the input signal therefore has to be correspondingly reduced for the required signal-to-noise ratio. In implementation of a single-bit sigma-delta converter this has to be dearly paid for, as a reduction in the noise power by 3 dB means that a capacity surface inside a corresponding semi-conductor circuit has to be doubled in order to reduce the dominant kT/C noise in a solution. An increased capacity surface or an increased capacity value is also here disadvantageously reflected in an increased current requirement of the corresponding semi-conductor circuit.
Therefore, a need exists in the art for a method and a device for analog-to-digital conversion, wherein there is no need to restrict the input signal.